1. Field of the Invention
The present invention relates to heat sinks, and more specifically to an improved vapor chamber heat sink that secures a component being cooled.
2. Background of the Related Art
Electronic components generate heat as a result of consuming electrical energy. A prime example of a heat-generating electronic component is a processor in a computer system, such as a central processing unit (CPU). A CPU directly accesses and executes software instructions from volatile memory, e.g. RAM (random access memory) or DRAM (dynamic random access memory). CPUs generate a considerable amount of heat as a result of performing numerous, extremely high-speed operations required for executing computer programs. The computer industry is continually innovating cooling systems specific to the unique and demanding cooling requirements of CPUs.
A heat sink is commonly used to cool a CPU. Generally, a heat sink conducts heat away from a CPU, and has cooling fins that provide a large surface area for airflow to efficiently remove the heat by convection. A variety of heat sink designs are known in the art, some of which incorporate a vapor chamber to improve cooling. A vapor chamber is a sealed vessel containing fluid that vaporizes in the vicinity of the hot component. The vapor migrates to a cooler surface of the vapor chamber, where it condenses and returns to the vicinity of the hot component. This vaporization and condensation cycle improves heat transfer from the hot component to the heat sink. For the purpose of this disclosure, a vapor chamber is defined to include a heat pipe as a particular type of vapor chamber.
Conventionally, a CPU is mounted in a connector known as a socket that is mounted to the system board. During assembly, the socket is soldered to the system board, and the processor is positioned in the socket, often as part of a CPU package that includes the processor and a substrate. A secondary retention structure is used to retain the processor within the socket. One example of a secondary retention structure is an Independent Loading Mechanism (ILM), offered by Intel®. The ILM resembles a picture frame hinged to one side of the socket. The ILM captures the processor, and a lever is used to urge the processor into electrical contact with the socket and to hold the processor securely within the socket. With the processor mounted, the heat sink is then secured to the system board over the ILM. The cooperating heat sink and ILM are subject to the mechanical design limitations imposed by one on the other. For example, the heat sink must be designed to account for the extra space required by the ILM, even though doing so may compromise the cooling capacity of the heat sink.